This invention relates to apparatus for ignition timing control systems for internal combustion engines.
Ignition control systems in current use typically provide for controlling ignition timing in response to conditions developed within the engine immediately prior to the igniting of the fuel charge. Angular velocity of the engines cam shaft and intake manifold vacuum, for example, are commonly used to regulate such timing. It has also been proposed, in U.S. Pat. No. 3,361,929, that firing chamber pressure be used to induce the spark plug firing for that chamber. While such prior arrangements have been improved over the years to provide a fair degree of reliability and accuracy, such systems nevertheless require frequent adjustment and such adjustment is oftentimes dependent upon the skill of the person performing the adjustment.
In recent years, it has been recognized as desirable, from a cost, performance, and reliability standpoint, to utilize electronic circuitry wherever possible in the operation and control of internal combustion engines and the like. Thus, alternators, electronic voltage regulators, electronic fuel injection systems and electronic ignition systems have been developed and are now widely used.
To my knowledge, there has not heretofore been available an electronic system for controlling the firing of a combustion chamber based upon an earlier comparison of the time maximum combustion pressure is developed in the chamber with the time a rotating member of the engine rotates through some predetermined optimum angular position at which the firing or maximum pressure ought to occur.